Burglar and fire alarm



Jan.. 1l, 1955 A. WARD BURGLAR AND FIRE ALARM Filed Oct. 6. 1950JNVENTOR. 5a/ A. WARD United States Patent O BURGLAR AND FIRE ALARMLeslie A. Ward, Cuyahoga County, Ohio, assignor to Morse Signal Devices,Cleveland, Ohio, a partnership Application October 6, 1950, Serial No.188,826

6 Claims. (Cl. 340-293) This invention relates to the art of burglar andiire alarms of the remotely supervised type and more particularly toapparatus for supervising burglar and iire detecting circuits andgenerating and transmitting coded signals to a remote supervisorycentral station in the event of an alarm.

Systems of the type to which this invention apply normally consist of anight protective alarm circuit and a day protective alarm circuit, bothpositioned on the premises to be protected. These circuits aresupervised by apparatus situated on the premises. In the event of anybreakage or alteration in the circuits, this apparatus generates andsends a coded signal over land telephone wires to a central supervisorystation.

The apparatus normally includes means for shifting from the night to theday protective circuit and vice versa, which shift must also send asignal indicating that the shift has been made and that the circuit isthen in normal operating condition. Further, the apparatus includes acode transmitter which is set into operation by any break in the nightor day protective circuit.

It is normally conventional for the transmitter at each premise underprotection to generate a distinctive identifying code signal. rThesupervisory station then analyzes the signal to determine the locationof the transmitter and the type of signalthat is, whether it is an alarmsignal or an opening or closing signal, and this is usually done bynoting the number of times that an individual coded signal is repeated.Thus7 in the event of a breakdown in a supervised protective circuit,the signal is repeated three times. dition, a fourth signal istransmitted, indicating that the system is back in normal operation. Ifany signal is received at an odd hour, it is considered an alarm signaland one to be investigated. If the fourth signal is not repeated at theopening or closing hour, the system is not in proper working order andshould be investigated.

Normally, the code transmitter includes a motor mechanism which drives acoding disk upon the happening of the above events to transmit therequired signal.

Heretofore such motors have normally been of the spring driven typewhich must be wound at spaced intervals or, in many cases, each eveningas the premises are vacated and placed under the supervisory control ofthe central office. the proprietor as he leaves and enters the premisesand may often not be done properly, resulting in an improper closingsignal and requiring investigation. Spring motors are dependable ifproperly wound. In the event the spring is not properly wound, as mayoften be the case, the transmitter cannot perform its prime function,that of sending an alarm signal.

To avoid the difficulties of a spring motor, it has been proposed toemploy an electric motor for driving the coding disks. These electricmotors may either be energized from the standard commercial power linesor from self-contained batteries. In the event of using the commerciallines and the power fails, no signal can be transmitted. The premisesare then unprotected. Actually the protection in such a case is notsufricient for the average commercial location. In the event batteriesare ernployed, these will become exhausted after a time even thoughthere is no drain on them so that the proper signal might not be givenwhen an alarm occurs. Renewing the batteries is an expensive procedure.Storage batteries have a habit of shorting out internally withoutwarning and they require maintenance.

lf the circuit is then restored to its normal con- Winding the motor isan inconvenience to rice The present invention contemplates burglar andre alarm apparatus of the type referred to for transmitting codedsignals to a central control station which overcomes all of the abovedifculties and combines the convenience of an electric motor poweredfrom commercial power lines for driving the coding disk with the overalldependability of operation of a spring Wound motor and yet does notrequire the periodical rewinding of the spring motor.

ln accordance with the invention, the apparatus includes in combinationan electric motor and a spring wound motor for actuating the codingdisks, the electric motor functioning for all normal uses and the springmotor functioning in the event that the commercial electric power shouldin any way fail, such as being cut by intruders, so that the electricmotor could not be actuated to send an alarm.

The invention has for its principal object a new and improved apparatusfor use in supervised fire and burglar alarm systems which is,primarily, dependable and fool proof in operation but is simple andconvenient to operate and requires a minimum of supervisory maintenance.

Another' object of the invention is the provision of a new and improvedtransmitter of the type referred to which includes in combination anelectrically driven coding means for generating all usual day-to-daysignals and a spring driven coding means for generating warningsignalsin the event the power for the electrically driven disc shouldfail.

The invention may be comprised of certain parts and arrangements ofparts in combination, a preferred embodiment ot which will be describedin this specification and illustrated in the attached drawing which is apart hereof and wherein the single figure shows a schematic Wiringdiagram of a burglar and fire alarm apparatus embodying the presentinvention.

Referring now to the drawing, wherein the showing is for the purposes ofillustration only and not for the purposes o'r` limitation, the burglaralarm circuit shown comprises day protective wiring 10 and nightprotective wiring lll, both adapted to be located about the premises tobe guarded for the purposes of detecting a burglary or tire. Trunk linesL1, LZ connect to a central oflce (not shown). An electric-motor drivencode transmitter A, and a springmotor driven code transmitter B, operateto generate a coded signal for transmission over the trunk lines. Analarm relay D associated with the night protective wiring lll controlsthe operation of the transmitter A, while an alarm relay E associatedwith the day protective wiring, controls the operation of thetransmitter B.

The trunk lines L1, L2 are electrically energized at the central controloce through suitable indicating equipment and the circuit between thetrunk lines L1, L2 is completed within the apparatus by a pair ofelectric contacts 35, 58, associated respectively with the transmittersA and B. These contacts 35, S3 are normally closed. When either thetransmitter A or B operates, however, the respective contact is openedto break the continuity through the trunk lines L1, L2, thus causing anindication on the equipment at the supervisory otce. Thus, to send asignal either Contact may be opened and a code signal may be sent oyopening either contact a predetermined number of times or in apredetermined manner.

The remainder of the apparatus is energized from any power source 2 suchas the local 110 volt alternating current power lines through atransformer 3 having a primary 4 connected to the source 2 and a lowvoltage secondary 5. A bridge rectifier 72 connects to the terminals ofthe secondary and provides D. C. for the protective circuits.

The day protective circuit l() is intended to give protection during theday or at other times when the premises under protection are occupied bythe owner or its employees and normally includes electric wiring inseries on doors, windows and areaways not normally used in the course ofa normal business day or in areas where the proprietor does not desireto have unauthorized entry.

The day protective circuit 10 is in electrical series relationship withthe energizing coil 65 of the relay E and is normally continuouslyenergized from the output terminals of the rectifier 72. The currentowing in this circuit is controlled by a series adjustable resistor 75.

The night protective circuit is in addition to the day protectivecircuit and is intended to give maximum full protection when thepremises are normally unoccupied and to this extent includes wiring onall doors, windows and areaways not otherwise protected by the dayprotective wiring 10. This night protective circuit includes anelectrical series relationship the energizing coil 40 of relay D and thecircuit is normally continuously energized from the output terminals ofthe rectifier 72. A variable resistor 85 controls the current flowing inthis circuit to near the threshold operating valve for the relay. Thus abreak in either protective circuit immediately deenergizes therespective relay.

The transmitter A is so constructed and arranged with the relay D as totransmit three complete coded signals in the event of any break in thenight protective wiring or in a shift from part to full protection orvice versa and one complete coded signal to signify that the system hasbeen restored to normal operating condition.

The transmitter A provides for positive transmission of all opening andclosing signals and also alarm signals without the necessity of anyinvolved procedure by the occupant of the premises to be guarded.

The electric motor transmitter A comprises a pair of cam disks 12, 13,mounted for rotation upon a common shaft 14. The shaft 14 is rotated ina clockwise direction by a synchronous A. C. motor 15, when energizedfrom the secondary of the transformer 3. Preferably the motor 15 drivesthe shaft 14 through suitablespeed reducing spur gears 16.

The transmitter A also includes a code disk 20 mounted on a rotatableshaft 21 which is geared to the shaft 14 through a set of spur gears 19having a gear ratio of l to 4, the shaft 21 rotating four times forevery full rotation of the shaft 14.

The cam disk 20 is for the purpose of opening and closing contacts 35and sending a coded signal to the central control office over the linesL1, L2 and for this purpose has a plurality of lobes 34 provided on itsouter edge which when the code disk is rotated by the motor 15 engagethe follower arm of the normally closed switch 35 to open its contacts.Depending upon the number and positioning of the lobes 34, any givencode signal may be sent. Normally a complete code signal is made up by acomplete revolution of the disk 20.

The cam disk 12 has approximately 90 of its periphery cut away, as at 22and a single pole double throw switch is provided having a cam-followeractuating arm 24, spring biased to ride on the edge of the cam disk 12.This switch includes a normally closed contact 25 and a normally opencontact 26.

The cam disk 13 has a pair of recesses 30, 31 in its periphery spacedapproximately 90 apart, which actuate a single pole, single thrownormally open switch 33 through a follower arm 34 which bears againstthe edge of the disk 13 holding the switch 33 closed and opening it whenopposite either recess 30 or recess 31. The re cess 30 is positioned onthe disk 13 so as to open contact 33 just prior to the time the disk 12will open contact 26. The recess 31 is positioned on the disk 13 so asto open contact 33 just prior to the time disk 12 will close contact 26.

For a three-quarter turn of the cam disks 12, 13, the cam disk 20 makesthree complete turns and three sets, that is an odd number of codesignals, are transmitted by the disk 20. For a one-quarter turn of thedisks 12, 13 one set of code signals are sent which, added to the oddnumber, makes a total of four or an even number.

The alarm relay D comprises an energizing coil 40 which actuates adouble throw, single pole switch having a normally closed contact 41 anda normally open contact 42. The relay also includes a normally opencontact 43. The energizing coil 40 is connected in series with the nightprotective wiring 11, and a current adjusting resistor 85 to the outputterminals of the bridge rectifier 72. Thus when the protective wiring isin its normal uninterrupted state, the coil 4t) is energized and holdingcontact 41 open and contacts 42 and 43 closed.

The spring wound transmitter B includes the contacts 58 and whenactuated transmits its own distinctive coded signal to the centraloffice. This transmitter serves two important purposes. The first is tosupervise the A. C. current supply and all circuit wiring from the powersource to and including all of the protective wiring. The second purposeis to provide a separate day protection circuit to which may beconnected all of the permanent protection devices and attachments withinthe premises so that a coded alarm signal is transmitted at any time ofthe day or night if the day protective circuit is opened or grounded.The transmitter B must be rewound after each such alarm and after thecause for alarm has been determined and corrected.

The term permanent protection is used to designate all protectionprovided for immovable openings, wall and ceiling surfaces, such as foilprotection on show windows, lacing and screen protection over skylights, panels on walls etc. Any alarms transmitted during the day oropen period are to be investigated and repairs made where necessary, orpower service restored before the customers regular closing time. Anyalarms received during the night or closed period are to be handled asattack alarms and investigated immediately.

The spring wound transmitter B shown comprises a cam disk 50 mounted forrotation on a shaft 51 and driven by a suitable spring wound motor 53.1n a like manner to the electric driven transmitter A, a code disk isprovided, mounted for rotation on a shaft 56 and driven from the shaft51 through a one to four gear ratio setY of gears 57. The code disk 55is similar to the code disk 20 and may have identically arranged lobes56 positioned on the edge thereof. These lobes actuate a normally closedswitch 58.

The cam disk 50 is provided with a single recess 60 on its periphery andactuates, through a follower arm 6l, normally closed switch 62 and anormally open switch 63.

The spring wound motor is limited to one full revolution by a stop 69which engages a dog 68 on the motor when the motor is manually wound byturning the shaft 51 counterclockwise and which again engages the dog 68when the motor has completed one full revolution. The location of therecess is such that when the motor is wound and the dog 68 engages thestop 69, the follower arm 61 is riding on the cam edge and the switches62, 63 are not actuated until the motor has moved approximately onequarter of a revolution at which point an armature 67 on the relay E mayengage the dog 68, if the relay is energized, and stop the motor 53.Rcenergization of the relay allows the motor 53 to operate for threequarters of a revolution.

The relay E includes an energizing coil in series with the dayprotective wiring 10 and the switch 62 and this circuit is energizedfrom the rectifier 72 when the switch 62 is closed so that the normalrest position for the motor 53 is as shown in the figures.

The arrangement is such that when the motor 53 is wound, a single codesignal will be sent. When an alarm occurs, three code signals will besent before the dog 68 engages the stop.

The control panel C includes three rotary selector switches 45, 46, 47,actuated by a single control knob 48. These switches are three positionswitches. The left hand position switch of each switch sets theapparatus in condition for detecting alarms during the day, the centralposition being for the purpose of detecting alarms at night, and theright hand position being for test purposes so that the owner of thepremises may determine that the apparatus is energized and connectedwith the central control office. A spring 49 biases the switch away fromthe right hand position.

In the embodiment shown the apparatus is set up to supervise twoseparate alarm circuits, a day protection alarm circuit 10 and a nightprotection alarm circuit 11. Such circuits are conventional and will notbe described here further except to say that they generally comprise along series electrical connection which if broken at any place orgrounded, breaks the entire alarm circuit. The variable resistors 75 and85 in series with the circuits are for the purpose of adjusting thecurrent in each circuit to a predetermined value generally justsufficient to maintain the relays D and E energized.

For the purpose of describing the operation of the equipment, it will beassumed that the owners of the premises are present such as might occurduring the course of any business day--in this event, the control knob48 would be in the day position-that is, pointed to the left. In thisevent, the switches 45, 46 and 47 are all in the open circuit position,and the relay coil is deenergized.

The alarm circuit with the central control oice includes the line L1,the normally closed switch 58 on the spring transmitter B, the wire 80,the normally closed switch 35 and the wire L2. It may be noted here thatthe switches 35 and 38 are in series electrical relationship so that theopening and closing of either may transmit a signal to the centralotiice. Switch 63 is in shunt with the switch 35.

The transformer 3 is energized from the source 2, which in turnenergizes wires 70, 71 at a voltage difference of approximately 24volts. This voltage is rectified by the bridge rectiiier 72 shown in thelower left hand corner of the drawing. The rectier 72 providesapproximately 18 volts D. C. output. This voltage appears across thewires 73, 74 which in turn establishes a current ow through resistor 75,the day protection circuit 10, wire `77, the energization coil 65 of thetrip relay E, Wire 78, the normally closed switch 62 to the wire 74. Itis to be noted that the wire 74 is grounded. The resistor 75 ispreferably an adjustable resistor and the current flowing lin thecircuit just described is preferably set to be approximately 30milliamperes. With such a current the trip relay E is actuated and themotor 53 may be wound. The relay E is conventional in construction andpreferably of the type that if the current is interrupted or increasessubstantially over the above value which might occur if portions of theday protective circuit 67 were shorted out, it will operate to permitthe motor 53 to start. lt will also be appreciated that as the rectifier72 is initially energized through transformer 3, any failure of the mainpower line will also serve to actuate the trip relay E and thereforestart the motor 53. If it be assumed that one of the above eventualitieshas happened and the relay E permits the motor 53 to start, the cam disk5t) commences to rotate in a clockwise direction. This immediatelyactuates the arm 61, opening switch 62 and closing switch 63. Opening ofswitch 62 breaks the circuit for the trip relay E so that the motor 53may continue to run. Closing of the switch 63 bypasses the switch 35 sothat if for any reason the motor 15 should start, two sets of signalswould not be sent at the same time.

As the cam disk 5t) is rotated, the code disk 55 is also rotated and thelobes 56 open and close the switch 58 in accordance with the positioningof the lobes. Each time the switch 56 is opened, a signal appears at thecentral control oice. The operator on duty at the central otiice canthen immediately dispatch people to the protected premises to determinethe diiculty. The signal is repeated three times, a warning signal.

Once the motor 53 starts, normally closed contacts 62 in series with theday circuit open, so that the relay will rliot be reenergized tointerrupt the sending of the signa Such a signal must be investigated.After the cause for the alarm is cleared, the motor 53 is wound byrotating it counterclockwise, one full turn. At this point the switch 62is open and the relay E deenergized. The motor 53 operates to send asingle signal at which time the switch 62 closes reenergizing the relayE, assuming everything else is in order.

At the time the owner of the premises desires to close up in theevening, he turns the control knob 48 all the way to the right or thetest position. This closes contact 83 on the switch 45 and completes acircuit from the wire 73 through the now closed switch 83, wire 84,resistor 85, wire 86, the night protection circuit 11, which is normallya closed circuit, wire 87, the energization coil 40 of the alarm relayD, to the wire 74, which energizes the alarm relay D, closing itsnormally open contacts 42 and 43 and opening its normally open contact41. This is the normal situation when the owner has left the premises,and when the knob 48 is released contact 88 of switch 45 will then beclosed and the contacts 83 and 87 are connected by a jumper wire. Withthe knob 48 in the test or right hand position, contact 90 of the switch47 is closed, completing a circuit from the wire 70 through the nowclosed contact 90, the wire 91, a test indicating lamp 92, the wire 93,the now closed normally open switch 43, to the wire 71, thus energizingthe lamp 92 and indicating to the occupant of the premises that thepower is on and that the night protection circuit 1s satisfactory andthat the alarm relay D is energized. In

6, addition, actuation of the switch 46 to the right closes contact 95,completing a circuit from the wire L1, the closed contact 58, the wire80 through the now closed contact 95, the wire 96, a 20 cycle buzzer 97,the wire 98, and a high capacity condenser 99, to the wire L2. With theknob 48 in such position, a 20 cycle A. C. signal sent over the controlwires L1, L2 will actuate the buzzer 97 indicating to the operator thatthe lines to the central control oice are in working order.

Upon release of the knob 48, the switches 45, 46, 47 return to theirinitial position. At this time the occupant of the premises must leavethe premises through a guarded doorway or the like. As he does so thenight protection circuit is broken, thus deenergizing momentarily thealarm coil D which opens its contacts 42, 43 and closes contact 41.Closing of the contact 41 completes a circuit from the wire 70, throughthe energizing coil of the motor 15, wire 100, closed contact 25, wire101, the now closed contact 41, to the wire 71, thus energizing themotor 15. The motor 15 immediately commences to turn, rotating the camdisks 12 and 13 in a clockwise direction and the cam 20 in acounterclockwise direction, the cam 20 rotating at approximately fourtimes the speed of the cam disks 12 and 13. As the cam disk 13 commencesto rotate it closes contact 33, cornpleting a circuit from the wire 71to the wire 100, thus bypassing the switches 41 and 25 and maintainingthe motor 15 energized even though the switch 41 should be reopened dueto reenergization of the alarm relay D. When the cam disk 12 commencesto rotate, it opens switch 25' but not before switch 33 has firstclosed, and closes switch 26 which completes the circuit from the wire103 to the wire 100. Closure of the contact 26 has no effect at thismoment as the contact 42 is open because the alarm relay D is notenergized. t.

The motor 15 will continue to operate until the cam disk 13 has advancedthree-quarters of a revolution, at which time the switch 33 opens, thusdeenergizing the wire 100 and the motor 15 stops. During the time thatthe cam disk 13 has been advancing its three-quarters of a revolution,the code disk 20 has made three complete revolutions, sending out threecomplete sets of code signals. This indicates to the operator in thecentral ollice that something is wrong, and that the operator has failedto close the door. It is to be noted at this point that the recess 22 onthe disk 12 is so disposed that its normally closed contact 25 will beopen and its normally open contact 26 will be closed.

When the owner or occupant of the premises closes the door as he leaves,the relay D becomes reenergized, thus opening contact 41 and closingcontact` 42, the wire 103, the now closed contact 26 to the wire 100,reenergizing the motor 15. Reenergization of the motor starts the camdisks 12 and 13 rotating clockwise again, closing the contact 33 andimmediately thereafter opening contact 26 and closing contact 25.Closing the contact 33 maintains the motor 15 energized even though thecontact 26 has opened. The motor remains energized until the cam disk 13has advanced clockwise one-quarter of a revolution when the contact 33again opens, deenergizing the wire 100 and stopping the motor 15. Duringthis onequarter revolution the cam disk 20 has advanced one entirerevolution, sending out a single code signal and indicating to theoperator at the central control office that everything is insatisfactory working order, behaving now received a total of four codesignals.

The specific apparatus above described is for the purpose ofillustrating the invention only. This embodiment is subject to manymodifications such as with limitation, the electric motor 15 and springmotor 53 may each drive the same coding disk either through over runningclutches or the equivalent. Also other known types of motors may be usedfor the supervisory transmitter B as full equivalents of that described.The important feature of the motor for the supervisory transmitter B isthat it be dependable and operable even though the means for operatingthe motor 15 of the main transmitter should fail.

The alarm relays may control the operation of their respective motorsother than that shown for example, the electric motor 15 may be of thetype that can be continuously energized while stalled without damage andthe relay D when energized may simply act to stall the motor somewhatsimilar to the operation of the relay 5 on the spring motor 53.

It will thus be seen that an embodiment of the invention has beendescribed which accomplishes the objects of the invention, and whichcombines the convenience of electric powered code transmitter with thedependability of self energy storing motors arranged in a supervisorysetup for the electric motor.

Having thus described my invention, I claim: I

1. In a remotely supervised alarm system, a fault detecting and signalgenerating arrangement comprising in combination,coded-signal-generating equipment and means for actuating same, saidmeans comprising a pair of motors each independently energized, one ofsaid motors being an electric motor and having a power source, a faultdetecting circuit, means for connecting said power source to saidelectric motor upon the occurrence of a fault in said circuit, and meansassociated with said power source for actuating the other of said motorsupon a failure of said power source, said last mentioned means alsobeing associated with means for detecting entry into said premises.

2. In a remotely supervised alarm system, a fault detecting and signalgenerating arrangement compris ing in combination, a pair of independentmeans for detecting entry into premises to be guarded, each of saidmeans including both a series electric circuit positioned about thepremises and an alarm relay normally maintained energized by electriccurrent owing in the respective circuit about the premises, a powersource for energizing both of said means, coded signal generatingapparatus including an electric motor and an independentlyenergized`motor, common electric circuit means adapted to communicatesaid apparatus with said central oice associated with said apparatus,one relay of one means connecting said electric motor to said sourceupon failure of relay energization, the relay of the other meansactuating the other motor upon failure of relay energization which maybe caused by a break in said electric circuit or failure of said powersource, in which latter event said electric motor could not operatewhereby said other motor then causes a signal to be generated.

3. In a remotely supervised alarm system, the new and improvedcombination of a day protective circuit and a night protective circuit,a day relay in series electrical relationship with said day circuit, anight relay in series with said night circuit; a power source connectedto each of said circuits and maintaining said relays normally energized,code generating apparatus, an electric motor for driving said apparatus,means operatively associating said apparatus with apparatus in a centralsupervisory oilice, said night relay including actuating means for saidelectric motor upon failure of energizing current in said night relay, asecond motor independently energized separate from said power source,said day relay including means for actuating said second motor upondeenergization thereof caused by a break in said day circuit or failureof said power source, and means for connecting said code generatingapparatus to a central supervisory station.

4. A burglar and/or fire alarm system of the remotely supervised type,including in combination a central supervisory oice; fault detectingapparatus on the premises to be protected; signal generating equipmenton the premises to be protected; electric power means on the premisesfor energizing said apparatus and equipment; a normally closedelectrical circuit communicating said office with said equipment andenergized at said oce; said equipment including a normally closed switchin series relationship with said otiiceequipment circuits and a drivencode wheel for opening and closing said switch; an electric motorenergized from said power source for driving said code wheel; meansoperatively associated with said motor and said apparatus for energizingsaid motor, manual means for energizing said motor; a second motorenergizedvndedependently of said power source for driving a code wheeland means for actuating said second motor upon failure of said powersource.

5. In a remotely supervised alarm system, a fault detecting and signalgenerating arrangement comprising in combination,coded-signal-generating equipment and means for actuating same, saidmeans comprising a pair of motors each independently energized, one ofsaid motors being an electric motor and having a power source, a faultdetecting circuit, means for connecting said power source to saidelectric motor upon the occurrence of a fault in said circuit, and meansassociated with said power source for actuating the other of said motorsupon a failure of said power source, said coded-signal-generatingequipment being in electrical series relationship with a signalelectrical circuit communicating with a central supervisory oice, saidcircuit being energized at said oice.

6. A burglar and/or fire alarm equipment adapted to be located onpremises to be protected and transmit coded signals to a centralsupervisory oliice over a single electrical circuit, said equipmentincluding a rotatable code disk; electrical contacts actuated by saidcode disk and adapted to be connected in an electrical circuitcommunicating with a supervisory station; rotatable cam members; switchmeans actuated by said cam members; an electric motor for rotating bothsaid code disk and said cam members, said cam and disk having a tixedratio of rotational speed; an alarm relay having a coil adapted to beenergized in electrical series with a fault detecting circuit on thepremises and including switch means actuated thereby, said switch meansbeing operatively connected to energize and deenergize said motor, saidswitch means and said cams being electrically connected as to rotatesaid switch means and said cams, and being so arranged as to rotate saidcode disks a predetermined number of turns when said alarm relay isdeenergized and a predetermined ditferent number of times when saidalarm relay is reenergized.

References Cited in the le of this patent UNITED STATES PATENTS1,124,799 Pool Jan. l2, 1915 1,479,555 Potter Ian. 1, 1924 1,613,802Mollard Jan. 1l, 1927 1,627,685 Beach May 10, 1927 2,170,104 WheelockAug. 22, 1939

